Wall-mounted suction ventilator

ABSTRACT

This invention provides a natural ventilator that is free of moving parts, wind-activated, rain-proof, and not only suitable to be a standalone natural ventilator but also advantageous to be used as an enhanced exhaust exit in a forced-air ventilation system. 
     The ventilator includes a base plate to be secured onto a substantially vertical exterior surface of such enclosed objects as a building or vehicle, a substantially horizontal tube connected to at least one opening substantially centered on the base plate, and a raised body being supported and secured on the base plate with elongated members and having a convex face towards the opening on the base plate. A free space is formed between the base plate and the convex face of the raised body. The convex face of the raised body is configured in such a way that the free space between the convex face and base plate is generally narrower near the opening on the base plate than away from the opening. This forms a first contracting and then expanding path for airflow to approach from any direction and to pass through the free space along the base plate, providing a venturi mechanism. The device thus creates a low air pressure in the free space near the opening and hence a suction effect therein, and communicates the suction effect to any interior space of a building or vehicle needing air relief or suction, through the substantially horizontal tube and any connecting conduit if needed. Several example designs for the tube illustrate methods to prevent rainwater from infiltrating into the interior space that is being vented and unsightly fume condensation from drifting outwards to the building or vehicle exterior. Such devices, as configured according to the spirit of this invention, provide for a simple suction ventilator that effectively prevents rainwater from infiltrating into the interior, even if raindrop trajectory becomes highly oblique from vertical as driven by strong winds. It also substantially stops unsightly fume condensation from drifting outwards to the building or vehicle exterior.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of Provisional PatentApplication Ser. No. 62/496,736, filed 2016 Oct. 28.

BACKGROUND Field of Invention

This invention relates to an improved air exhaust system, which can beutilized in the field of building and vehicle ventilation.

Discussion of Prior Art

U.S. Pat. Nos. 4,223,486; 4,557,081; and 4,888,930 to T. L. Kelly,Waterbury, Conn. taught a method to equalize or balance the uplift onthe upper surface of roof membranes by channeling the negative pressuretherein to underneath the membrane, as well as to aid venting outmoisture there under.

That method, while intended to tap the negative pressures that occurabove the roof, has the potential to actually feed positive pressureinto underneath the membrane, enhancing the uplift force so as to worsenthe situation. This is because of the fact that the wind flow on theroof is highly turbulent and complex, frequently deviating from thesituation the Kelly equalizer system is designed for. The method is alsonot suitable for wall-mounted applications. Particularly in wall edgeareas the airflow is dominated by strong, fluctuating and intermittentvortices. Pressures therein fluctuate significantly from negatives topositives as evidenced in wind tunnel and field test data. Positivepressure will completely counter Kelly's intention with his device.Although the Kelly method also includes a valve intended to “prevent”any positive pressures from entering into underneath the membrane, theair tightness of the contracted valve sleeves is hardly sufficient toblock out the infiltration of positive pressures. Such additionalmechanism also complicates the system, increases the probability orchances of component and system failure, and raises the cost of thesystem as well.

In the field of building and vehicle ventilation, a number of designsexist for aiding air exhaust or air relief, for example, U.S. Pat. Nos.6,582,291 B2; 6,302,778 B1; 5,326,313; 4,379,972; 4,086,028; and3,952,638 to various inventors. However, none provides a simple andeffective method. Most of them involve complicated and expensive movingparts such as turbines, fans and associated bearings etc., which alsoincrease the chances of mechanical failure.

U.S. Pat. Nos. 7,001,266; 4,963,761; 4,603,619; 4,534,119; 3,509,811;3,382,792; 3,347,147; 3,345,931; 2,387,708; and 211,872 to variousinventors disclosed ventilators utilizing venturi effects; however, thedisclosed configurations are all vulnerable to rainwater infiltrationinto the interior, and are complicated and lead to higher material andfabrication costs.

U.S. Pat. No. 7,065,271 to Lin, U.S. patent application Ser. No.11/177,492 of Jones et.al, and Ser. No. 12/101,625 of Lin disclosedventilators that resolve rainwater infiltration concerns by usingcomplicated air path with multiple turns, but such methods have alsocompromised highly-desired aerodynamic effectiveness for ventilation, aswell as led to still relatively higher material and fabrication costs.

SUMMARY OF THE INVENTION

With a direct gas exit, along with new rainwater-proof mechanisms, thepresent invention provides a simpler roof-mounted gas exhaust device, orso-called suction ventilator, that is foolproof in ensuring “negativepressure” or suction at the exit under any external flow condition,which can be used for aiding air relief or ventilation in buildings,other enclosed facilities, vehicles or trailers. The external flowcausing the suction can be from natural wind or due to the motion of avehicle, on which the suction ventilator is installed.

By disposing the ventilator's exit opening or openings towards acontracted free space between a base body and a raised body, a venturieffect is created at the opening under natural wind where low-pressure,or so-called suction, draws air from inside the exit and into theexternal wind flow to be carried away. The faster the wind flow is, thelower the pressure becomes at the exit opening and the stronger thesuction effect.

The ventilator disclosed herein has a direct gas exit without multipleturns of gas conduit, reducing drag to the gas flow and improving theventilator's effectiveness, while still possessing a rainwater-proofproperty.

The low pressure generated at the exit opening is significantly lowerthan the internal pressure inside a building, vehicle, or compartmentstherein, and other enclosed objects or units, under essentially allexternal wind conditions. This effect lends the ventilator afunctionality of aiding air exhaust, natural or forced, for theventilation of spaces in buildings, enclosed facilities, vehicles orother enclosed objects and units that are connected to the ventilator.The ventilator disclosed herein is improved for forced air exhaustbecause it facilitates direct air exit without multiple turns of airconduits such that it presents less drag to air flow, while maintaininga rainwater-proof property.

The designs disclosed herein provide for a suction ventilator thateffectively prevents rainwater from infiltrating into the interior, evenif raindrop trajectory becomes highly oblique from vertical as driven bystrong winds.

OBJECTS AND ADVANTAGES

Accordingly, several objects and advantages of the present inventionare:

to provide a foolproof air exhaust ventilator that ensures “negativepressure” or suction at the gas exit under any external flow conditionfor improved air relief in buildings, enclosed facilities, vehicles,trailers or other such enclosed objects and units;

to provide a ventilator of zero energy consumption that uses onlyexternal natural wind energy;

to provide a device that obviates any moving parts, such as turbine, fanor bearing etc., which are expensive and often represent the sources ofmechanical failure and render an exhaust system malfunctioned, and thusrepresents a reliable and durable device of low cost, low maintenance,low failure probability, long life expectance and no mechanical noise;

to provide a device that has relatively simple configuration and theease to manufacture and install, whereas is still among the mosteffective and efficient;

to provide a ventilator that is rainwater-proof, smog-proof anddust-proof, while having a direct exhaust exit to reduce drag to gasflow and increase effectiveness, efficiency and thus usefulness;

to provide a ventilator that is most suitable to be mounted on asubstantially vertical surface as situation requires;

Further objects or advantages are to provide a ventilator that is amongthe simplest, most lightweight, most inexpensive to manufacture andconvenient to install, no troublesome moving parts, zero energyconsumption but high exhaust efficiency, rain and smog infiltrationproof These and still further objects and advantages will becomeapparent from a consideration of the ensuing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates one of the preferred basicconfigurations according to the present invention.

FIG. 1a shows a slight modification to the configuration on therain-proof mechanism according to the present invention.

FIG. 2 illustrates another of the preferred basic configurationsaccording to the present invention.

FIG. 3 shows an exemplary modification to the configuration in FIG. 2according to the present invention.

FIG. 4 shows an alternative configuration according to the presentinvention.

FIGS. 4a and 4b illustrate modifications to the configuration in FIG. 4according to the present invention.

FIG. 5 shows another alternative rain-proof mechanism that is acombination of those in FIGS. 4a and 4b according to the presentinvention.

FIG. 6 shows further another embodiment according to the presentinvention.

FIG. 7 shows an exemplary configuration modified from that in FIG. 6according to the present invention.

FIG. 8 shows an embodiment of the present invention for a suctionventilator that consists mainly of plane surfaces.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates one of the preferred basic configurations of thepresent invention, for a side view as being mounted to an exterior wallsurface 10. A raised body 120 is supported with a plurality of elongatedmembers 130 onto a base plate 140, which is attached and secured ontothe exterior wall surface 10 with any appropriate means. The raised body120 has a convex surface facing the base plate 140, such that a freespace 110 between them is narrower near its center than toward its outerperimeter, forming an airflow path that first contracts and then expandsunder any approaching wind direction. The base plate 140 has an openingapproximately at its center forming an exit of a tube or tunnel 150 thatpenetrates the wall and channels the spaces inside and outside a wallenclosure. The number and size of the support members 130, hollow orsolid, should be sufficient to support the raised body 120 but not beexcessive to over-occupy the free space 110 formed between the raisedbody 120 and the base plate 140. When external airflow passes the freespace, which may be caused by wind or by a moving vehicle, itaccelerates while approaching the center of the free space so that thepressure therein becomes negative relative to the ambient pressure asgoverned by Bernoulli principle, called venturi effect. The higher thewind speed, the stronger the negative pressure will be. This negativepressure, or so-called suction, induces a secondary flow 100 through thetunnel 150 and its exit towards the free space 110, providing constantexhaust from an interior space within the wall enclosure under anypossible ambient or external wind speed and direction. This suction canbe channeled, with any appropriate means such as a conventional duct orconduit, to a specific space in a building, vehicle or trailer, forexample, a kitchen, bathroom or lavatory therein, for ventilationpurposes, improving air flux. This is applicable not only as astandalone method of natural ventilation, but also in mechanicallyforced ventilation scenarios. Examples of such forced ventilationscenarios include kitchen range hoods and bathroom fans, where a deviceof this invention is used as the exhaust exit of such ventilationsystem, enhances the exhaust efficiency with its suction mechanismdescribed above, and prevents air backflow under any possible ambientwind speed and direction whether the system's mechanical forcing such asa fan is on or off The raised body 120 and supports 130 are preferablyhollow to save material and reduce weight of the system; however, it canalso be solid without affecting their respective functionalities, whensystem weight and material cost are lesser an issue than other suchfactors as manufacture complexity, for example, when using certainlightweight synthetic material.

An optional ring-like liner 105 can be fitted or mounted into thetube/tunnel 150 as shown in FIG. 1, to stop rainwater from driftingthrough the tunnel 150 into an interior space being vented via thedevice, and to prevent unsightly residual fume condensation, depositedon the inner portion of the tunnel 150, from drifting outwards to theexterior wall surface. One of the preferred shapes of such liner 105 (orliners) is as shown in FIG. 1, which functions as double drip edges and,by having a wider top and a narrower bottom, ensures any rainwaterdripping from the outer drip edge of the liner being kept outside andany fume condensation dripping from the inner edge being kept insidewhere fume condensation is normally more convenient to clean than thaton an exterior wall. Other liner shapes are possible according to thespirit of this invention.

FIG. 1a shows a slightly modified shape of the liner 105a, having anarched upper portion that enhances the liner's functionality as doubledrip edges to prevent rainwater from drifting inwards and unsightly fumecondensation from drifting outwards.

FIG. 2 shows an alternative configuration for preventing rainwater fromdrifting inwards, where the tunnel 250 is sloped to shed liquidsoutwardly. This alternative tunnel configuration is not recommended foruse in such situation as a kitchen or a range hood in kitchen, whereheavy fume condensation may occur in the tunnel 250, since condensedfume droplets may drift outwards over time to reach and stain theexterior wall surface.

FIG. 3 shows another alternative configuration for preventing rainwaterfrom drifting inwards and unsightly fume condensation from driftingoutwards, where the tunnel 350 is sloped to shed liquids outwardly onits outer portion and inwardly on its inner portion.

FIG. 4 provides another alternative configuration for preventingrainwater from drifting inwards and fume condensation from driftingoutwards, where the bottom of the tunnel 450 is sloped to shed liquidsoutwardly on its outer portion and inwardly on its inner portion. Asingle drip edge 452 is formed at the upper part of the joint of the twoportions that helps stop any rainwater invaded on the upper tunnel wallfrom drifting further inwards or any residual fume condensation fromdrifting further outwards.

FIG. 4a provides a modified configuration better for preventingrainwater from drifting inwards, where the drip edge 452 a is formed andskewed outwardly to ensure that rainwater will not drip into the innerportion of the tunnel 450 a.

FIG. 4b provides another modified configuration better for limiting fumecondensation from drifting outwards, where the drip edge 452 b is formedand skewed inwardly to ensure that fume deposit will not drip into theouter portion of the tunnel 450 b.

FIG. 5 provides a further modified configuration better for bothpreventing rainwater from drifting inwards and limiting fumecondensation from drifting outwards, where two drip edges 552 a and 552b are formed and skewed inwardly and outwardly respectively to ensurethat no or little liquid drips into a wrong side of the ridge 551 in thetunnel 550.

FIG. 6 shows another design of the tunnel 650, similar to the tunnelshown in FIG. 4 but with a curved tunnel wall. The lower wall surface ofthe tunnel 650 is curved down in both directions from the ridge point651 to shed rainwater outwardly on its outer portion, and unsightlycondensation inwardly on its inner portion. The lowest portion 652 ofthe upper wall surface helps stop any rainwater invaded on the upperwall from drifting further inwards, or any residual fume condensationfrom drifting further outwards. A better option for restrictingrainwater, similar to that in FIG. 4a , is to position the low point 652of the upper surface in FIG. 6 further outward, relative to the ridgepoint 651 of the lower surface. On the other hand, similar to that inFIG. 4b , a variation better for confining fume condensation is toposition the low point 652 of the upper surface in FIG. 6 further inwardrelative to ridge point 651.

In FIG. 7, upper drip edges 752 a and 752 b, which are ring-like convexribs circling about half of the upper wall of the tunnel 750 andpreferably slightly beyond, and a lower divider ridge 751, circlingabout half of the lower wall of the tunnel 750 and preferably slightlybeyond, are added to form an alternative tunnel configuration 750. Sucha design ensures that no liquid drips into a wrong side of the dividerridge 751.

The specific shapes shown in the previous figures for the raised bodyand other elements of the suction ventilator are merely used as examplesto assist in illustrating the general conception. Variations areallowable for their shapes, such as modifications to the ratio of heightto width, or aspect ratio, of the raised body. Specific choices ofcross-sectional shape, length and diameter of the tunnel, as well asthose of the elongated supports for the raised body, are also allowableaccording to the situation of application as desired and appropriateaccording to the spirit described herein.

For example, configurations primarily comprising plane surface areacceptable. FIG. 8 shows an example of such alternative configurations.The raised body 820 is formed of multiple plane surfaces. The respectivecross-sectional shapes of the tunnel 850 and elongated supports 830 canbe square or rectangular.

Other aesthetically pleasing or appealing modifications to the shape ofthe raised body are allowable in principle as long as such modificationswill not jeopardize or significantly compromise its aerodynamicfunctionality, for which its general shape that has a convex surfacefacing the tunnel exit should be substantially maintained. Non-smoothsurface, for example, roughened, corrugated or ribbed, can be utilizedfor the raised body, for whatever purposes—architectural, aerodynamicsuch as for flow separation control or airflow guide etc., or anyothers, as long as such local additions do not significantly alter thegeneral shape of a convex surface facing the tunnel exit.

Optional removable or fixed screens may be installed on any suitablelocation in the tunnel, for example the tunnel 850 in FIG. 8, to preventflying insects or small birds from invading the system or an interiorspace being vented.

Installation and Operation

In principle, the suction ventilator described herein is functionalanywhere on a vertical or near-vertical exterior surface of the buildingor vehicle where there are relative air movements, such as those causedby wind or by a moving vehicle, although there are optimal locationswhere installed suction ventilators will function most effectively.Generally, these locations are near edges and corners, where airflowvelocity is normally the highest and local ambient air pressure islowest most of the time.

Suction ventilators described in this application are passive,flow-activated devices.

Once installed properly, they stay operating and functioning as windblows, and require no active intervention. The stronger the wind blows,the more effective the suction ventilator is. Since there is no movingpart involved in the entire system, minimal or no maintenance isrequired. Routine cleaning may be needed in situations with heavy fumecondensation, mostly for the portions of the system reachable frominside a building or vehicle without the need for specialty cleaningequipment.

Conclusion, Ramifications, and Scope

It is apparent that suction ventilators of this invention provide an airor gas exhaust system that is aerodynamically advantageous, energyconserving, rainwater-proof and fume condensation reducing, and is stillamong the simplest, most inexpensive to manufacture and convenient toinstall. Unlike other ventilation options, such as exhaust fans orturbine vents, it involves no moving part or mechanism, so that it alsopossesses many additional qualities desired of a ventilator, includingextremely low maintenance, essentially unlimited life expectancy,noise-free operation, and so on.

Although the description above contains many specifications, theseshould not be construed as limiting the scope of the invention but asmerely providing illustrations of some of the presently preferredembodiments of this invention. Various changes, modifications,variations can be made therein without departing from the spirit of theinvention. For example, the outer perimeter edge of the raised body canbe a sharp edge, instead of being a blunt edge as shown for all theabove given examples. The suction ventilators can be made of anyreasonably durable material with any appropriate means of fabrication aslong as a configuration according to the spirit of this invention isaccomplished to support the described working mechanism and to providethe associated functionality. Various surface portions of a suctionventilator may also be roughened or bear such surface details ascorrugation or ribs of adequate sizes, as opposed to perfectly smoothsurfaces. Any appropriate conventional or new surface-mounting methodcan be used to secure a suction ventilator to a vertical ornear-vertical surface without departing from the spirit of thisinvention. Thus the scope of the invention should be determined by theappended claims and their legal equivalents, rather than by the examplesgiven.

What I claim as my invention is:
 1. A device to be most suitably mountedonto a substantially vertical exterior surface of a substantiallyenclosed object to be vented, comprising: a mounting base suitable to besecured to said exterior surface and having at least one aperturelocated substantially at or near center of said mounting base; a tubebeing connected to said aperture to allow for free movement of gasesthrough connected assembly of said aperture and tube; a raised bodyhaving a convex face towards said mounting base, being substantiallyco-axial with said aperture and tube, and being supported and secured onsaid mounting base with a plurality of elongated members, forming a freespace between said convex face and said mounting base; wherein said freespace being generally narrower near said aperture than away from saidaperture, forming a first contracting and then expanding path forairflow approaching from any direction and passing through said freespace between said convex face and said mounting base, whereby to createa low air pressure or a venturi suction effect at said aperture, saidsuction effect to be communicated to an interior space of said enclosedobject to be vented when connected to said tube and aperture.
 2. Thedevice of claim 1, wherein said raised body and/or at least one of saidelongated members being hollow.
 3. The device of claim 1, wherein saidtube having at least one internal ring-like liner, therein to stopresidual rainwater from drifting inwards and unsightly fumecondensation/droplets from drifting outwards along inner wall of saidtube.
 4. The device of claim 3, wherein said liner having an upperportion wider than lower portion, therein to serve as double drip edgesand to further ensure rainwater droplets to fall on outer portion ofsaid tube and fume droplets to fall within inner portion of said tube,said outer portion and inner portion being separated by said liner. 5.The device of claim 4, wherein said upper portion of said liner beingarch-shaped, having lowest points at inner and outer edges, therein toenhance functionality as double drip edges.
 6. The device of claim 1,wherein said tube having a slope downwardly and outwardly.
 7. The deviceof claim 1, wherein outer portion of said tube having a first slopedownwardly and outwardly, and inner portion of said tube having a secondslope downwardly and inwardly.
 8. The device of claim 1, wherein outerportion of said tube expanding outwardly, and inner portion of said tubeexpanding inwardly, juncture of said inner and outer portions forming anarrowest cross-section of said tube, upper portion of said narrowestcross-section forming a drip edge and lower portion of said narrowestcross-section forming a dividing ridge.
 9. The device of claim 8,wherein said narrowest cross-section inclining outwardly such that saiddrip edge being located outward side of said dividing ridge.
 10. Thedevice of claim 8, wherein said narrowest cross-section inclininginwardly such that said drip edge being located inward side of saiddividing ridge.
 11. The device of claim 8, wherein said junctureincluding two narrowest cross-sections, forming two drip edges and atleast one dividing ridge, first narrowest cross-section incliningoutwardly such that first said drip edge being located outward side ofsaid dividing ridge, and second narrowest cross-section inclininginwardly such that second said drip edge being located inward side ofsaid dividing ridge.
 12. The device of claim 1, wherein said tube havingat least two internal upper-wall convex ribs as drip edges and at leastone internal lower-wall convex rib as dividing ridge, first saidupper-wall convex rib being outward of said lower-wall convex rib, andsecond said upper-wall convex rib being inward of said lower-wall convexrib.
 13. The device of claim 1, wherein said aperture and/or said tubehaving protection screens, therein to prevent flying insects or birdsfrom entering said aperture and/or tube.